High-temperature alarm for internal-combustion engines



Dec. 29, 1925. 1,567,616

O. RABE HIGH TEMPERATURE ALARM FOR INTERNAL COMBUSTION ENGINES FiledApril 16, 192s Patented Dee. Z9, l925 GTT() BABE, OF V/"ILMETTE,ILLINOIS.

'HIGH-TEM'EERATRE ALILRTY .FCR lJTERNAL-COMBUSTON ENGINES.

To all 'whom it may concern:

Be it known that l, OTTO ltr-inn, a citizen f the United States,residing at llVilmette, in the county of Cook and State of Illinois,lia-ve invented certain new and useful lmproveinents in High-TemperatureAlarms for Internal-Combustion Engines, of which the following is aspecification.

This invention has to do with certain imrovements in high temperaturealarms for internal combustion engines. The invention relates toimprovements in high temperature ala-rms for internal combustion enginesused for the propulsion of motor vehicles such as automobiles, trucks,tractors, and the like, which are driven by internal combustion engines;but it will presently appear that the'device can also be used toa-dvanta-ge in connection with internal combustion engines for otherpurposes.

More particularly the invention relates to certain improvements in analarm for use in connection with the cooling medium which is used injacketed internal combustion engines. Still more particularly, the alarmof the present invention is so constructed as to give an audible signalwhen the temperature of the cooling water, for example, exceeds acertain point.

The audible alarm to which the present application particularly relatesmay be used in conjunction with the cooling liquid of the jacket in anydesired manner, provided that the device be subject to changes oftemperature With the temperature changes which take place in the jacketmedium. For example, this device can be used in such a manner as to besubject either to the exact temperature of the jacketing medium itselfor to the temperature of the air or steam within an enclosed space abovethe j acketing medium.

ln some cases the device of the present invention may also be used forindicating an excessive temperature in the cylinder walls themselveseven when said cylinder walls are not provided with any j acketingmedium for cooling purposes. In such case the device can be used, forexample, for indicating an excessive temperature in the cylinder wallsof an air cooled engine.

The main object of the present invention is t0 provide an alarm orsignal device which shall operate very accurately at the desiredtemperature range Where the signal is to be giyen, notwithstanding thefact that the said temperature range may be considerably above thenormal temperature of thel surrounding atmosphere. n

In connection with the foregoing, a further object of the invention toprovide an arrangement such that a very long thermal element may beused, said thermal element being so shaped that it can be brought into avery small amount of space.

A further object of the invention is to so arrange the construction thatthe thermal element will operate to give a rotary movement to thestripping device by a direct operation, and without the need of usingany longitudinal movement of a thermal element afterwards converted intoa rota-ry movement.

In connection with the foregoing, a still further object of theinvention is to provide a construction such that the thermal elementtogether with the actuating device, which connects the same with thesignal mechanism, may be removed or inserted as a unit and without thenecessity of interfering with the construction and operation of theother parts of the device. This will make it possible to insert orremove or adjust the thermal element itself together with the connectionto the signal mechanism without having to disassemble the entire device,and also with a great reduction and saving in the amount of labor andcost of the same.

A further benefit derived from this arrangement is that the cost ofmanufacture is considerably reduced and also the` various parts can beassembled or adjusted in the hands of the user without difficulty, ifneces- Sarg.

ther objects and uses of the invention will appear from a detaileddescription of the same, which consists in the features of constructionand combinations of part-s hereinafter described and claimed.

ln the drawing:

Figure l shows a longitudinal section through an alarm device embodyingthe features of the present invention, the same being applied to theradiator cap of a motor vehicle, so that the thermal element is subjectto the temperature existing within the air space above the water withinthe radiator of the motor vehicle;

Fig. 2 is a view at right angles to that of Fig. l;

affita Fig. 3 is a detailed cross section taken on the line 3 3 of Fig.1, looking in the direction of the arrows;

Fig. 4 is a fragmentary sect-ion on the line 4-4 ot Fig. 1, looking inthe direction of the arrows, the thermal element being in the normalposition in which the operation ot the signal or alarm is interferedwith; and

Fig. 5 is a view similar to that ot Fig. 4, with the exception that thethermal element has been turned due to rise ot temperature so as todisengage the alarm device and allow the same to function.

rThe particular construction shown in the drawing includes an alarmdevice designated in its entirety by the numeral 6, which, in thepresent instance, is adapted to give an audible signal as by the ringingof a bell oi the like. Furthermore, the signal device, as hereinillustrated, is shown as being mounted upon the radiator cap 7 whichthreads into the neck 8 of an automobile radiator, so that the signaldevice will be operated by the temperature existing within the air space9 above the water in the radiator. 1 wish it distinctly understood,however., that in showing this particular' application of the invention,l do not intend thereby to limit its use to the intluence ot thetemperature wit iin the air space above the water, since manifestly, astar as the signal device itsel't is concerned, it can be used in anyconvenient manner or combination.

The signal device and thermal element 10 which is preferably mountedWithin a bracket or open shell 11, tie sides of which are cut away, asshown in Fig. 2, so that the thermal element itself is directlysubjected to the temperature ot the medium which is to be measured.

T he lower portion et the thermal element is rigidly connected to theplug 12 which sets into av socket in the lower end 13 ot the bracket 11.The lower end ot the bracket may be clamped against the plug 12 by theuse ot a sleeve 14 which is threaded onto the lower end 13 with a taperthread, so that when the sleeve 14 is tightened up, the lower end 13will grip the plug 12 and prevent it from turning. The arrangement issuch that rotation ot the plug 12 will turn the thermal. element bodily.rlLhe clamping eftect on the plug 12 may be secured by squeezing thelower end 13 of the bracket 11 or in any other suitable manner.

The thermal element itselt' is preferably "termed ot a relatively narrowthin strip of metal which has high temperature co-etli cient otexpansion; and, in fact, it may be desirable in some cases to use acompound strip ot two metals having different co-etiicients ofexpansion, so that as the tempera.- ture rises the strip bends. 0naccount ot the great length of the strip (made possible within arelatively small space by the spiral element), the upperend 15 ot thestrip willV be subjected to a very considerable change of position w'tha relatively small change ot temperature.

Furthermore, by reason of the spiral form ot the thermal strip, changesof temperature will result in a rotary or turning mhovement at its upper.end 15, as distinguished trom a direct up and down thrust, and by usinga strip of consic erable length twisted into a number ot convolutions(tour in the case illustrated in 1), it is possible to secure a verysubstantial fbange ot angular position oie the upper end of the striowith a relatively small change oi temperature. @wing to the that thelower end of the stripl is anchored by anchoring the plug 12, it tollowsthat all ot the rotary movement. produced by change ot temperature isconcentrated at the upper end 15.

l make use ot the rotary movement or' the upper end 15 'for the purposeot' tripping the signal device when the temperature reaches the criticalpoint. The construction illustrated in the osent case is as follows: Aplug 16 is rotatably mounted in the base portion. 17 of the signaldevice. the` lower end ot the plug 16 being slotted, as shown at 18 inFig. 3, so as to receive the extreme end portion 19 t the thermal strip.rlhe two sides 20 and 21 ot the slotted portion of the ilug 13 may beclamped firmly against the end 19 of ie therin i al element in order tocause the plug 1G to respond exactly to changes ot angular positions ofthe upper end of the thermal eleinen The extreme upper end ot' the plug1G is slotted as shown at 22 Figs. 4 and 5. rlhe alarm device oit theconstruction illustrated in the drawing includes a bell 23 which isadapted to be struck by the hammer 24 c rried by the nger 25'which canbe operated by a Swiss movement 25, or in any other convenient manner.The arm 25 is received in the slot 22 of the plug 16. lf'iThen the plugis turned into the position ot 5, the slot 22 allows tree movement ofthe arm 25, so that the signal is given, but at other times the arm 25is held by a bind-v ing action, due to the tact that the plug 16 is notturned into the proper position.k

lormally, the plug 16 is held in such position as to bind the arm 25 andprevent it from moving, as shown in Fig. 4. llVhen the temperaturereaches the point at which the signal is to be given, the upper end ofthe thermal element has been twisted around so as to turn the plug 15 asutlicient amount to disengage the arm 25 and allow the signal to begiven.

1t will be noted that with the arrangement herein disclosed, it ispossible to insert or remove the thermal elementtogether with the plug1G at its upper end, and the plug lil 12 at its lower end by directapplication upwardly through the bracket 11. Consequently, in order toinsert or remove the thermal element together with the plug 16 it isonly necessary to loosen up the sleeve 14. It is unnecessary with thisconstruction to either solder or unsolder any parts, and the necessarychanges or adjustments can, therefore, be made in a very simple manner.

The temperature at which the alarm device will be released, can beregulated by turning the plug 12 within the lower portion 13 of thebracket 11, since this will alter the temperature at which the angularposition of the slot 22 will disengage from the signal device. The plug12 can be easily turned by the use of a screw driver working in thecross slot 2? of the plug, after loosening up the sleeve 14h Thecalibration of the device can easily be performed by inverting the cap'i' having applied thereto the signal device as a unit, and thereuponplacing within the inverted cap and around the thermal element a liquidhaving the temperature at which it is desired for the device to give asignal. The plug 12 can then be turned to the exact point where thesignal is just given which will represent substantially its properposition for giving the signal at the desired temperature.

As a matter of convenience in construction, the bell and other parts maybe mounted within a case 28 which has the base flange 17 adapted to seatagainst the top surface of the radiator cap 7 either' directly orthrough the medium of a companion collar Q9. A neck 30 reachesdownwardly from the base 17 through the cap 7, its exterior beingthreaded to receive a locking nut 31 on its under side. A lock washer 32may be placed between the nut 31 and t-he under face of the cap, ifdesired. Furthermore,

the nut 31 may be provided with a downwardly depending cylindricalflange 33 which is spaced away from the bracket member 1l a sufficientdistance to allow easy circulation of liquids or vapors or air aroundthe thermal element, the lower end of the member 33 being open in orderto allow the same to enter and gain access to the thermal element.

While I have herein shown and described only a single embodiment of thefeatures of my present invention, still I do not limit myself to thesame except as I may do so in the claim.

I claim:

In a device of the class described, the combination of a casing adaptedto be mounted on the i'iller cap of a radiator or the like, a clock workbell alarm within the casing including a striker normally operated bythe clock work, a downwardly depending exteriorly threaded hollow neckon the casing adapted to reach through the filler cap, there being aninternal circular recess in the lower portion of said neck, a spiralthermal element within the neck, a plug rotatably seated within thecircular recess aforesaid, a rigid connection between the lower end ofsaid thermal element and said plug, a rotatable shaft secured to theupper end of the thermal element and reaching upwardsinto the casingaforesaid, there being a transverse notch in the upper end of said shaftreceiving the striker, the thermal element normally turning the shaft tothereby grip the striker and restrain the same from operation, and meansfor clamping the lower end of the neck for the purpose of clamping theplug against rotation therein, to thereby hold the plug in an adjustedposition substantially as described.

OTTO RABE.

